Cellular and genetical aspects of interactions between hosts and fungal symbionts in mycorrhizae

Abstract

Contact between appropriate mycorrhizal symbionts initiates a cascade of events that leads to modifications in the behaviour of both organisms at cell and tissue levels and the establishment of a functionally compatible relationship. Mechanisms that regulate the outcome of the symbiosis must involve a complex interchange of signals that triggers changes in genome expression in either symbiont. Analysis of symbiosis-specific proteins, interspecific grafting experiments, and the obtention of fungal and plant variants with phenotypes deficient for mycorrhiza formation provide information to help unravel the molecular and genetical puzzles of fungus–host interactions in mycorrhizal associations.Key words: mycorrhiza, cellular relations, host mutants, fungal strains, interspecific grafting.